The bracket assembly for lifting and supporting a foundation relates to L shaped foundation brackets in general and more specifically to improvements in the connections of the bracket to a pier for supporting a foundation. A unique aspect of the present bracket assembly is a removable gate and adjustable bolt that position the bracket assembly upon a pier to resist moment, translation, and rotation of a bracket.
The bracket assembly transfers the weight, or load, supported by a foundation, or footing, to a pier, pile or deeper foundation. The bracket assembly commonly cradles a footing, or foundation wall, of a structure, or building, then transfers the load to a pile or pier that bears on bedrock or other load bearing strata beneath the existing foundation. The main concept of this invention is to support a settling foundation Prior art designs have previously supported failed or shallow footings.
Piers made of concrete, reinforced concrete, timber, steel pipe, steel tubing, and solid steel bar bent into a helix have seen use at many sites to remedy failing foundations with varying success. The adequate transfer of the load from the foundation to the pier concerns contractors, engineers, and owners alike. Commonly, contractors place piers below a foundation by jack-hammering through a foundation, often through a basement floor. Piers directly below a foundation become impractical because of overhead height constraints and damage to an existing structure. To minimize risk, contractors excavate wider access holes lest, piers become too short. Short piers have proven cumbersome and time consuming for contractors and result in a pier of questionable flexural rigidity.
The present art overcomes the limitations of the prior art where a need exists for a bracket to adequately transfer the foundation load to a pier located adjacent to a foundation. That is, the art of the present invention, a bracket assembly for lifting and supporting a foundation, fixes a bracket to a pier with minimal moment and rotation of the bracket when under load. As a key feature, the bracket assembly reduces the distance between the pier and the foundation to minimize the moment induced into the top of a pier by an eccentric load from the foundation. The moment imparts bending upon the pier where the pier has the lowest lateral support from adjacent soil and tends to rotate a bracket away from the corner of the foundation. The rotation educes the effective bearing area between the bracket and the foundation. The gap exposed by a rotated bracket gives the appearance of a weak connection.
The difficulty in providing a bracket assembly is shown by prior art bracket designs that transferred a foundation load to a particular style of pier. In U.S. Pat. No. 5,120,163 to Holdeman et al., U.S. Pat. No. to 5,171,107 to Hamilton et al., and U.S. Pat. No. 5,246,311 to West et al. each describe a bracket for a specific style or size of a pier. Some prior bracket designs state a feature to accommodate different sizes and styles of piers but, only provide for partial front to rear engagement between the installed pier and a bracket. Typically, an installed pier has a clearance between the lower portions of the bracket and the front edge of a pier toward the foundation.
In U.S. Pat. No. 6,079,905 to Ruiz et al. for example, the adjustable brackets only engage the upper portion of the bracket and the back edge of an installed pier farthest from the foundation. The prior art brackets provide little means of contact between the lower portion of the bracket and the front edge of a pier towards a foundation. Under typical loads without contact at both the lower front and the upper rear edges of the pier, the prior art brackets rotate about an axis perpendicular to the length of a pier. Rotation causes the foundation support portion of a bracket to disengage from a foundation opening a gap, thus reducing the effective load capacity of a bracket. Contractors and owners alike desire a bracket assembly adaptable for various shapes and sizes of piers and adjustable to prevent rotation and moment between a bracket and a pier. Thus, the present invention has the ability to fully support the foundation upon the bracket, to maintain such, and to prevent slippage between the bracket and the supported foundation.